Fans of the first three Bourne movies will want to see this fourth franchise installment, The Bourne Legacy, which--as the title implies--is a kind of homage. Those who have never seen the previous films (The Bourne Identity, The Bourne Supremacy, The Bourne Ultimatum) will definitely want to see those movies before seeing Legacy. Otherwise, the complex plot, which references the previous films, will be confusing to the point of exasperation. I did see and greatly enjoy the previous Bournes, but was dizzied at what the heck was going on in this new take. No doubt this is the end of the franchise.
At least the trailer is brief: https://www.youtube.com/watch?v=jSzy9qQ3mDE